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LM4871: USB2.0 Audio 10W solution

Prodigy 665 points

Replies: 8

Views: 72

Part Number: LM4871

Hi team

The customer wants to know if we have a 10W~20W usb2.0 audio solution. The power of their old projects is only 4W and they want to update a high power solution

Old project:

USB2.0 -> CP2615 -> LM4871 -> Speaker

I am wondering if you could give a TI's solution to meet the customer's update? It seems that LM1875 is a good replacement to meet the customer's requirements.

Thank you.

  • Hi, Stone,

    Our team will take a look at this thread and will reply as soon as possible.

    Best regards,
    Luis Fernando Rodríguez S.

  • Hi Stone,

    We don't have a simple solution for this, but we can suggest some power amplifiers.

    What is the power supply requirement for the application?

    • TAS2563 is our latest smart amp, this can up to 6.1W into a 4ohm speaker. It uses an internal Class-H boost to step up a ~5V supply.
      • If higher supply voltage is available, it can be configured in boost-bypass mode where PVDD can be supplied by up to 16V, and output is able to reach 10W.
    • TAS2770 is a Class-D amplifier with no internal processing features and PVDD can be supplied up to 18V and can output up to 20W into a 4ohm speaker.

    Regarding the USB-to-Audio device unfortunately we don't have a device with this feature.

    Best regards,
    -Ivan Salazar
    Applications Engineer - Low Power Audio & Actuators

  • In reply to Ivan Salazar:

    Hi Ivan

    Thanks for your information.

    The following signal chain is accurate and please ignore the project described in the original post. The available power trail in the customer's board is 24V, 12V, 5V, 3.3V

    USB -> CP2615 -> ES7144 -> LM4871 (x2) -> Speaker (x2) 

    The customer wants to keep the 2 speakers and update the power from 3W to ~10W per speaker. I am wondering if you could help answer the following questions:

    • Is it okay to use TAS5805M (Powered by 12V)to replace "ES7144 -> LM4871 x2"? 
    • The USB1.1 is also acceptable for the customer, could you help recommend a TI's total solution to meet the customer's requirements?

    Thank you.

  • In reply to Stone Wang:

    Hi Stone,

    I think TAS5805M is a good replacement for LM4871+ES7144. Any further questions you have about TAS5805M I encourage you to create a new thread for that specific device.

    Regarding USB to audio, I'm not aware of any device that does this, you could upload a post on the processors forum and check if they have any proposal.

    Best regards,
    -Ivan Salazar
    Applications Engineer - Low Power Audio & Actuators

  • In reply to Ivan Salazar:

    Hi Ivan

    Based on the customer's old project:

    USB -> CP2615 -> ES7144 -> LM4871 (x2) -> Speaker (x2) 

     

    I think we have two USB audio solutions with a higher power:

    Solution1:

    USB -> TI's Audio USB converter (Like PCM2903C) -> TI's high power amplifier (10W output power, like TPA3138D2) -> Speaker (x2) 

    This would be a total TI solution. From my understanding, the question here is that the USB interface only supports USB1.1.

    Solution2:

    USB -> CP2615 -> TAS5805M -> Speaker (x2) 

    Just use TAS5805M to replace LM4871+ES7144, it's easy to update for the customer.

    I am not sure if my understanding of this system is correct. What are your thoughts?  Which one do you recommend?

     

  • In reply to Stone Wang:

    Hi Stone,

    I agree with both solutions.

    1. I though you could only use digital signal converter from USB. My bad to make this assumption. Unfortunately as you mention I think we only support USB1.1 for PCM29xx devices.
    2. As mentioned on previous post, this is a good solution to replace 2 chips for only 1.

    I think the solution would depend on application requirements:

    • Solution 2 reduces part count, and it takes directly from digital data to the speaker.
    • Solution 1 would be an effortless development, all is hardware controlled in this solution.

    By the way, I have some experience with PCM2903C and TPA3138D2, but actually all three parts mentioned belong to MPAA team.

    Best regards,
    -Ivan Salazar
    Applications Engineer - Low Power Audio & Actuators

  • In reply to Ivan Salazar:

    Hi Stone,

    Did the above post help you?
    Do you have further questions?

    Thanks and Best regards,
    -Ivan Salazar
    Applications Engineer - Low Power Audio & Actuators

  • In reply to Ivan Salazar:

    Hi Ivan

    Very clear about it. Thank you.

    Finally the customer plan to adopt solution 2 because of the USB2.0 interface.